Mr. Glass

Hello,

I drive a 2001 E320 (4MATIC) with about 48,000mi.

Both of my catalytic converters have been rattling mildly-moderately (depending on the day), and a local mechanic who I trust told me a few months ago that their condition is not too bad and that I can just leave them if I don’t mind the noise. I live in Florida, so no inspection or emissions testing are required.

About a week ago, I got an oil change (from a new mechanic, closer to my new job) and a few days later, my check engine light started flashing and then stayed solid. The next day, I brought it back to this new mechanic, who had performed my oil change.

He said that his OBDII reader stated that two of my coils are bad. He is recommending the following service:

-Change all coils, plugs, and wires - $739.00+ Tax
-Replace both catalytic converters - estimated $1500-$2500 depending remanufactured or new MB parts.

He didn’t mention the oxygen sensors, but based on what I’ve been reading on here, it seems like that may or may not be needed also.

I am dropping the car off at my original, trusted mechanic tonight, for a second opinion tomorrow.

I wasn’t expecting $3000+ of repairs and will have a really hard time affording it, so I could definitely use any advice I can get. Different people have been telling me different things, but do you have any insight on whether the bad cats caused problems with my coils and plugs or vise-versa?

Would it be ok to just service the coils, plugs, and wires for now and then wait on the cats?

I have heard mixed opinions regarding aftermarket cats like MagnaFlow and could really use some advice in this regard. Ideally, I’d like to keep road noise as quiet as possible.

Thank you for any insight you can provide.


Best Regards,

Glass

Plutoe

Not knowing what state you reside, but does that state have emission testing, if they do then they just answered your question---if not screw the cats and wait till the 02 sensors crap out!!

Mr. Glass

Thank you for your reply.

Here is an update on my situation:

My trusted mechanic took a look, plugged in his scanner, and concluded that nothing serious was wrong. He told me I can keep driving it until the cat becomes plugged up and impacts my acceleration.

I drove it back from the shop today, and on the way home, my speed dropped to about 30MPH on the highway and my RPM increased dramatically. I assume that this is the cat plugging up? I pulled off the road and called a towing service to take me the rest of the way home.

I believe that I should now replace the cats. I plan to call a few muffler shops tomorrow to get quotes. What do you recommend regarding a reliable aftermarket cat that is compatible with my 2001 E320? I live in Florida, so emissions are not an issue.

Should I still have the plugs changed? If I don’t do so right away, do I risk damaging the new cats?

Is it ok for me to slowly drive it to a local muffler shop in this condition, or should I call in another tow?

Thank you again for your advice.


Best Regards,

Glass

W210Wagon

When my cat failed, it was just one side. My 98 E320 has 4 cats, 2 for each bank. When the front one failed it took out the back one also. The car still drove almost normally. Acceleration and throttle response were obviously hurt. My local muffler shop replaced 2 cats on the drivers side bank for $600. They did not use the OEM cats. They were not louder than stock. They seem to work just fine except much cheaper than OEM.